Art of cracking hydrocarbons



sept; l2, al1 93o.,

QE. w; llsoM E1' AL ART l0F CRCKING H-fDRocARBoNsv A mx @fxww Patented Sept. 2, 1,930

UNITED STATES A PATENT orne-E EDWARD WQ Isom, or scAnsDALE, NEW Yoan, AD'EUGENE C. HERTEEI., or CHICAGO,

ILLINOIS, 'assumons 'ro sINcLAIn REEINING COMPANY, or NEW Yoan, N. Y., A

conrona'rIoNpF-MAINE j ART or cnAcKING nYDnocAnBoNs applicati@ mediana 11,

sure 1stilla'tioncracking operations.

' The present invention provides a combined.

operation including a novel heating operation of special value and application inconjunction with pressure distillation, o'r socalled pressure shell, cracking operations.

The invention will be described in connection with the accompanying. drawings which illustrate, diagrammatically and convention-l ally, apparatus embodying and for carrying out the invention. In theY accompanying drawings,vFig. 1 re resents, in elevationand partly in section an with parts broken away,

. apparatus embodying and adapted for carrying out thev invention and Fig.- 2 is a-fragmentary section through and )ust above the lower ends of the heating tubes illustrated in :ferring to the drawings, a stream of high boiling oil is forced, by means of pump 2, through a batter of series connected banks of series connecte vertical heating tubes arranged in a vertical heating Hue in heating furnace 1 into the vapor separating receptacle 3 from which vapors are taken off under superatmo'spheric pressure, the oil being heated to a cracking temperature during passage through the heating tubes. The battery ofheating tubes consists, as just mentioned,

of a plurality of series connected banks 11,

12, 13, 14, 15, 16, 17 and 18 of heating tubes each of which banks consists of a plurality of series connected heating tubes. These several banks of heating tubes are arranged transversely to the general direction'of travel of the heating gases entering the upper end of the vertical heating flue in which these banks of heatingtubes are arranged so that the heating ases entering the upper end of the heating ue ow across the several banks of heating tubes in succession, first across bank 11, then across bank 12, then across'bank 13 and so on, in inverse order with respect to the oil liow therethrough. The heatingV gases enter the upper end of the vertical heating flue 4 through passage '5 from the rebox 1929. serial no. 370,096.

6, in which fuel is burned for supplying heat to the operation, and after passing across and back and across the heating tubes while loW- ing generally downwardly through the heating flue 4 escape through stack iiue, 7. The

oi-l flowing through each bank 4of heating tubes flows successively upwardly and downwardly through the series connected heating tubes formin the bank. The oil supplied to thebattery o series 'connected banks of heating tubes, through connection 8, Hows first through bank 18,.then through bank 17, then through bank 16 and so on, until discharged Vfrom bank 11 through connection 9. Thus,

the heating gases' from l the irebox 6 pass across th-e upper end of the heating flue 4, as theyenterit through passage 5, passing first over the heating tubes comprising the bank 11 through-which the oil supplied to the bat-- tery of heating tubes last passes, then over the bank 12, then over the'bank 131and so on, and these heating gases then pass generally downwardly through the heating flue 4 overA the heating tubes comprising the several banks to the stack flue 7.

' The vapors taken off from the vapor se arating receptacle' 3,. through connection 10,

are subjected to a ref'luxing operation in re' iluX'toWer 19 from whi ch theyaporsremaining uncondensed escape through connection 20 to the condenser 21 arranged to discharge `into the receiver 22 from which a condensed distillate product -is discharged through connection 23 ,and uncondensed vapors and gases through connection 24. The pressure in the vapor separating .receptacle 3 is maintained yand regulatedby means of valve 25, or ,by

means of suitable valves arranged beyond the condenseror receiver. Raw' oi'l is supplied to the reluXing operation through connection 26 by means of pump 27, and utilized therein. as a direct refluxingmedium for effecting *and controlling the operation. Admixed reluxfcondensate and raw oil are supplied to the battery of heating tubes arranged in the heating furnace 1 from the refluking operation through connections28 and 8 by means of pump 2. Residual oil is discharged from the vapor-separating receptacle 3 through connection29.

In initiating operation, oil is circulated' from the vapor separating receptacle3, by means of valved connection 30, through the battery of heating tubes and back to the Vapor separating receptacle until normal operating conditions ofltemperature-and pressure are reached, the valve in connection 30 being closed during normal operation. Connection 31, communicating through valved.

branches with the lower ends of each ofthe heating tubes, is provided for pumping out the battery of heating tubes at the end of a run. The initial charge of oil, at the beginning of arun, is supplied through connection 32, and the vapor separating receptacle pounds per square inch, for example, and the oil forced through the battery of heating tubes may be heated therein to a temperature approximately 8251-875o F. as discharged through connection'9 into the vapor separatin'g receptacle 3, for example. The rate at which ra-w oil is supplied through connection 26 may be regulated to condense in the refluxing operation all constituents higher boiling than suitable as components ofthe desired distillate product, and residual oil may be discharged through connection 29 at a rate regulated to ymaintain a uniform liquid level in the vapor separating receptacle 3.

In the apparatus illustrated, the vapor separating receptacle 3, the reflux tower 19,

and connections 9, 10, 28 and 8 are with advantage thoroughly lagged or thermally insulated.

The heating furnace 1 may, with advantage, be arranged and operated as 'described in Letters Patent Nos. 1,574,546 and 1,574,547 issued to Sinclair Refining Company, February 23, 1926, on application of the late John EaBell or as described in Letters Patent No. 1,623,773 issued to Sinclair Refining' y Company, April 5, 1927, on application of the late John E. Bell.

The present invention has a number of advantages. The combination of vertical oil flow and high velocity oil flow in the heating operation minimizes'any tendency toward deposition of pitch or carbon in the heating tubes. The arrangement of the heating tubes is peculiarly compact and permits the use of a gang cleaner. with maximum advantage. The heat exchange relations between the heating gases and the oil being heated to a cracking temperature, provided by this invention, are peculiarly effective in pressure distillation cracking operations.

We claim: In the manufacture o`f lower boiling hydrocarbpn oils from higher boiling hydrocarbon oils, the improvement which comprises forcing a stream of high boiling oil through a battery of series-connected banks of seriesconnected vertical heating tubes arranged in a vertical heating iiue into a'vapor separating receptacle, passing heating gases from a firebox in which fuel is burned for supplying heat to the operation across the upper end of said'heating flue first in heat exchanging relation with the o il in the bank of heating tubes through which the oil last passes and then in heat exchanging relation successively with the oil in the other banks ,of heating tubes in inverse .order with respect to the oil flow therethrough and then passing Lhe heat- 4ing gases generally downwardly through said heating Hue in heat exchanging relation with the oil in the several banks of heating tubes, and thereby heating the oil toa cracking temperature, and taking olf vapors including vapors of thedesired low boiling oil from said vapor separating receptacle under superatmospheric presure.

In testimony whereof we afiix our signatures. EDWARD W. lISOM.

EUGENE QIIERTHEL. 

